The present invention relates to a method and device for promoting a localized change in the flow of blood through a blood vessel, and more particularly, to a non-invasive method and device for promoting a localized change in the flow of blood by electrically-induced contractual movement of muscular tissue.
Current treatments for improving blood circulation and alleviating neural and muscle pain include manual, electrical, and mechanical methods. Manual treatment as practiced in physiotherapy requires massaging to be administered by qualified personnel. The efficacy of this personnel-intensive art varies with the experience and technique of the individual massage therapist, and therefore cannot be prescribed in an adequately standardized form. More importantly, the improvement in blood circulation is also of an extremely limited magnitude.
Electrical Muscle Stimulation (EMS) has seen widespread use in many applications. The Food and Drug Administration (Section 355.200 Electrical Muscle Stimulators, CPG 7124.26) maintains that EMS devices are recognized in the health care community as being effective for muscle reeducation, relief of muscle spasm, increasing range of motion, disuse atrophy therapy, increased local blood circulation, and immediate post-surgical stimulation of calf muscles to prevent venous thrombosis. It must be emphasized, however, that the stimulation provided by EMS is very similar to the stimulation achieved by therapeutic massage. Any increase in blood circulation is so modest that it is often undetectable using conventional flow-measuring equipment. EMS is a random excitation of a local tissue area. Hence, EMS methods, like therapeutic massage, hot-water treatments, etc. are incapable of providing a major increase in the localized flow of blood. Moreover, because the excitation is random, EMS methods are fundamentally incapable of providing a decrease in the localized flow of blood.
Also known is a sequential pneumatic device for the reduction of an edema. The device consists of several overlapping compartments contained in a sleeve assembly. The compartments are inflated in a sequential fashion, from a distal end disposed adjacent to the edema, to a proximal end, such that the edema is pressed in the proximal direction. Each compartment is filled with air by a pump. The cycle starts with the filling of the distal compartment, and subsequently the remaining compartments are filled until all compartments are full. After a deflation period, the cycle is repeated.
This and other treatments employ electromechanical installations in which electric motors and reciprocating mechanisms create uncomfortable noise and vibration. These treatments are of further disadvantage in that they require various device elements to be contacted with the skin. These elements generally cause discomfort to the patient, and require changing and cleaning after each use in order to ensure good sanitary conditions.
U.S. Pat. No. 5,674,262 to Tumey teaches a device and method for stimulating blood flow velocity in a leg, in an effective and relatively painless manner, so as to prevent deep vein thrombosis. The device includes a mechanical compressing apparatus for compressing a foot so as to drive a substantial amount of blood from veins of the foot into blood vessels of the leg, and a second apparatus, operably associated with the compressing apparatus, for electrically stimulating leg muscles as the driven blood from the foot passes therethrough. The resultant muscle activity enhances the blood flow velocity to the point where endothelial derived relaxing factor (EDRF) is produced, which dilates the blood vessel and enables a higher flowrate of blood to be delivered.
Significantly, U.S. Pat. No. 5,674,262 teaches that electrical stimulation, in and of itself, is not efficacious for stimulating blood flow, and does not bring about EDRF production.
U.S. patent application Ser. No. 10/451,334 to Nachum teaches treatment methods for promoting a localized increase in the flow of blood through a blood vessel in an area of the body. In these treatment methods, electrical impulses from the signal generator are applied to body tissue, by means of electrodes, so as to subject the adjacent muscular tissue to at least one voltage differential, thereby inducing a repeated, contracting movement of muscular tissue associated with the local blood vessels. This movement of muscular tissue produces a localized increase in the flow of blood through these blood vessels.
In preferred embodiments, treatment is effected by placing the electrodes at opposite ends of the limb segment, and applying the electrical impulses so as to establish a voltage differential between the electrodes. The voltage differential is made up of two wave forms propagated in opposite directions between the electrodes.
U.S. patent application Ser. No. 10/451,334 teaches that the timing between these wave forms is critical, and that there should be a time overlap between them of 1 to 500 microseconds, and more preferably, between 10 microseconds and 100 microseconds. It will be appreciated that in practice, the requisite synchronization is difficult to achieve, such that the method is of limited efficacy.
There is therefore a recognized need for, and it would be highly advantageous to have, an improved, efficacious device and method for more efficiently promoting, upon demand, the localized circulation of blood through blood vessels. It would be of further advantage if the device and method would be simple, robust, non-invasive, repeatable, and adjustable to the individual needs of the patient.